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Why Do Some Animals Hibernate?

AnimalsBiology

Quick Answer

Hibernation conserves energy during winter when food is scarce by drastically slowing metabolism, heart rate, and body temperature.

The Full Story

Hibernation is an extreme energy-saving strategy. Animals such as bears, ground squirrels, and bats enter a state of torpor where their metabolic rate can drop by over 95%. A ground squirrel, for instance, lowers its body temperature from 37 °C to as low as -2 °C and its heart rate from 200 beats per minute to about 5. This allows the animal to survive months without eating by slowly burning stored fat. The trigger is usually a combination of shortening daylight, falling temperatures, and dwindling food supplies.

Key Facts

1.A hibernating black bear can go over 100 days without eating, drinking, urinating, or defecating.
2.The Arctic ground squirrel is the only known mammal whose body temperature drops below freezing during hibernation.
3.Some species of frogs survive winter partially frozen, with up to 65% of their body water turning to ice.

YouTube Angle

Suggested video title for this topic:

"How Animals Survive Winter — The Science of Hibernation"

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